Velella Velella Washes Ashore Along Pacific Coast Beaches in Spring Aggregation

Hundreds of thousands of velella velella washed ashore along the coasts of California, Oregon, and Washington in an event that drew particular notice in Southern California. Douglas McCauley, director of the Benioff Ocean Initiative at the University of California, Santa Barbara, observed the creatures stretched along the entire length of a beach in late April 2026 while conducting a great white shark observation project.

"In a lifetime of living and doing marine science in Southern California I've never seen that many pile up on a beach," McCauley said.

Recent aggregations of velella velella along beaches and just offshore have been especially dense along the California coast. Flotillas of velella velella often come ashore along the Pacific Coast in the spring when offshore winds shift. One study along the coast of Washington state suggested larger concentrations of velella may be found after particularly warm winters.

Such events often occur in spring when winds shift, and some studies have noted higher numbers following warmer winters. U.S. Pacific Coast and in the Mediterranean, said Rebecca Helm, assistant professor of environmental science at Georgetown University's Earth Commons Institute.

They drift and float for thousands of miles on the ocean's surface and have triangular-shaped sail features that allow ocean winds to push them along. Velella velella eat zooplankton, fish eggs and krill. Ocean sunfish, or mola mola, have been seen feasting on large flotillas of velella at sea.

Rebecca Helm is studying the coating on velella that helps repel water and keep them upright. Scientists still have much left to learn about the creatures despite documentation for decades. Steven Haddock, a senior scientist at the Monterey Bay Aquarium Research Institute and an adjunct professor at the University of California, Santa Cruz, stated that scientists do not yet fully understand velella velella.